How We Talked from the Moon

Dr. Rob SuggsNN4NT

NASA Marshall Space Flight Center

GNU Radio Conference 2019

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How they got the sounds and videos back to Earth

The sounds of Apollo

The key is USB

Extreme SWL

Lots of options for comms

In living color - eventually

We’re gonna do it again

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The iconic “beeps” were used to push-to-talk from Mission Control to the ground stations

The Quindar tones were used to command ground stations into transmit and back to receive over phone line from Mission Control

Intro 2525 Hz Outro 2475 Hz

transmit listen

Constant S-band carrier was sent to the spacecraft for trackingPRN code from ground was returned by spacecraft and range was determined

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The Apollo Snoopy Cap carried the headphones and microphones

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NASA TM X-55492 1966

The magic is USB – Unified S-Band System

8https://www.ab9il.net/images/apollo-usb-transponder.jpg

Unified S-bandSystem

Both spacecraft had numerous antennas for S-band and VHF

Command Service Module 4 omni antennas were body-mounted

4 dish High Gain Antenna

Lunar Module2 omni antennas

2 VHF + 1 for linking EVA crew to Earth

1 S-band high gain and 1 radar dish

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NASA TM X-55492 1966

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85 foot dish at Honeysuckle Creek Australiahttps://www.honeysucklecreek.net/station/index.html

12NASA TM X-55492 1966

“Houston, Tranquility Base here…”

13NASA TM X-55492 1966

Hams received some S-band from the CSM in lunar orbit

14From QST June 1972

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Richard Knadle K2RIW and Paul Wilson W4HHK independently received the Apollo 15 signals

1612 ft diameter wire mesh dish

K2RIW Feed horn made from American paint canand Scottish oatmealcan

Heard Al Worden in Apollo 15 CSMin lunar orbit and crewduring return cruise.13.2 w 2287 MHz

From QST June 1972

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K2IRW’s system used some amateur radio components

Richard is still activeon 10 GHz and VHF/UHF

There were better results with Apollo 16

Detected Lunar Module carrier and from doppler could see touchdown

Detected Earth-based uplink via EME

Detected 1W signals from ALSEP scientific packages

18From QST July 1972, World Above 50 MHz

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Apollo 16 ALSEP

Apollo Lunar Surface ExperimentsPackage

1W S-band

Passive Lunar Seismic ExperimentLunar Tri-axis MagnetometerMedium-Energy Solar WindSuprathermal Ion DetectionLunar Heat Flow ManagementLow-Energy Solar WindActive Lunar Seismic ExperimentSNAP-27 isotopic power system

The S-band and VHF systems allowed various direct and relay configurations

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https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090015392.pdf

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https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090015392.pdf

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https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090015392.pdf

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https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090015392.pdf

Television used B&W vidicon detectors

Video used S-band auxiliary signal bandwidth ~ 0.4 MHz (broadcast TV uses 6 MHz)

Black and white was 10 frames per second of 320 lines

Standard video was generated at the ground station by pointing a camera at a 10 fps screen, recording that to a magnetic disk and replaying that frame 5 times to create 30 fps (60 fields/sec)

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How to get color TV from a B&W vidicon

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200 lines, 60 fields per second = 2 MHz bandwidth signal which required significant filtering to avoid interference from other S-band components

Video tape was used to correct video sync for doppler

A magnetic disk recorder spinning at 3600 rpm (1/60 sec) recorded RGB on 6 separate tracks which were read simultaneously with multiple heads and combined to produce a standard color video signal

www.youtube.com

eyesofageneration.com

spaceflight.nasa.gov

2 each, RGB10 rev/sec

S-band antennas enabled color video

Apollo 11 used LM dish for

B&W video

Apollo 12 and 14 used fixed cameras and dishes

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Apollo 15, 16, and 17 had pan/tilt/zoom camera and dish antenna on lunar rover

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ArtemisReturn to the Moon

Boots on the Moon by 2024

Space Policy Directive 1 (Dec. 2017) – return to the Moon and on to Mars

In March VP Pence directed NASA to land humans near the lunar south pole by 2024. Original planning was for 2028.

Sustainable lunar exploration will be done with Gateway and the Human Landing System (transfer, descent and ascent elements)

HLS elements will be aggregated at Gateway and Ascent Element will be reused

Space Launch System (SLS) and Orion will ferry the crew and some of the hardware

Commercial launches will transport some of the hardware and logistics

ApolloCommand/Service Module (with crew) and Lunar Module were launched together on Saturn V

nasa.gov

Orion

nasa.gov

20190723_nextep-h_virtual_industry-forum.pdf

Gateway Phase 2US and international partners

nasa.gov

nasa.gov

Lunar south pole illumination map

https://quickmap.lroc.asu.edu/layers?extent=-112.4216008,-84.630363,117.5697916,-83.4670082&proj=17&layers=NrBsFYBoAZIRnpEB2Bb4F0saA

nasa.gov

For More Information

“How Apollo Flew to the Moon” W. David Woods

NASA Technical Report Server sti.nasa.gov

search for unified s-band system

apolloinrealtime.org/11/

QST June and July 1972

quickmap.lroc.asu.edu

trek.nasa.gov

20190723_nextep-h_virtual_industry-forum.pdf

nasa.gov

Gateway orbit

space.stackexchange.com

nasa.gov

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nasa.gov

www.freereplublic.com

www.lpi.usra.edu

Voice and telemetry subcarriers

52From QST June 1972

53From QST June 1972

Gateway 2024 conceptnasa.gov

Saturn Telemetry

• C-band transponder on Instrument Unit – 5400-5900 MHz, 10 MHz bandwidth

• 700 W nominal transmit power

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Manned Space Flight NetworkApollo 14 stations

https://www.honeysucklecreek.net/msfn_missions/MSFN/index.html

W4HHK’s system also used some amateur components

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18 foot dish

W4HHK became a Silent Key in 1999. Call is now held by Collierville Millimeter Wave Society

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NASA TM X-55492 1966